Focus Media (Kigali)

The water hyacinth is suffocating lakes in Akagera National Park, threatening many species as well as tourism activities. Yet environmental specialists do not agree on what method to use to wipe it out.

A lake has reportedly dried up and many others are under siege by the free-floating water hyacinth

The lake in questions is Lake Mihindi, which has been infested by the invasive aquatic plant for many years. Many others, including Lakes Gishanju, Shakani, and Ihema, are also critically affected by the water weed, according to local tourism experts.

The experts say that tourism in Akagera Park could be affected greatly if the current rate of spread of the water hyacinth is not checked.

According to the University of Texas's Center for Aquatic plants, water hyacinth is one of the worst weeds in the world - aquatic or terrestrial. Its growth rate is among the highest of any plant known: hyacinth populations can double in as little as 12 days. Its floating mats can weigh up to 200 tons per acre.

According to Edwin Sabuhoro of Ecotours, a local ecotourism company, these floating mats greatly affect the parks ecosystems (both water and land ecosystems), and in the end impact on tourism.

As he explains, the floating mat created by the hyacinth is a threat to the big, as well as the small aquatic animals; the hippopotamus and elephants are affected, just as are the small fishing birds, fish and the microscopic plankton they feed on.

Both ecosystems in the park in danger

Some of the species most threatened by the disappearance of the water bodies are hippos, crocodiles, and the shoebill stork. The hippos are blocked by the thick hyacinth mat from pushing their heads out of water to breath. Likewise they are trapped when they try to get out of the water to feed at night.

The shoebill stork is one of the rare birds that nests on water islands and mashes within the Akagera lake system. The fish eagle is also one of the biggest tourist attractions of Akagera. Together with the kingfisher, their livelihoods are threatened as the water hyacinth blocks their view of the fish in the water. "As the water bodies dry, we are loosing these rare and highly attractive species", says Sabuhoro.

The fishing sport, also a big tourist attraction in the park is greatly affected. Water hyacinth infestations prevent sunlight and oxygen from getting into the water. Decaying plant matter also reduces oxygen in the water. The result is death of fish. In addition, the thick cover of the water

hyacinth makes movement of fishing boats impossible, not to mention swimming.

Sabuhoro further says that Akagera National Park stands out because it is the only park in Rwanda with two ecosystems. Tourists like Akagera because it has both savanna and a chain of lakes, he says. However, these two ecosystems are interrelated so that if one is affected, the effects spillover to the other. He cites the example of elephants that use the lakes for bathing to cool their body temperatures.

Mechanical or biological method?

Tourism experts and environmentalists fear that not enough emphasis has been put on the fight against the water hyacinth; it poses a real threat to the countries biological diversity and tourism. The Rwandan Office of Tourism and National Parks (ORTPN) however says it is doing everything possible to keep the water weed under control.

According to Fidele Ruzigandekwe, ORTPN's Director of Conservation, the fight against the water hyacinth has started with Lake Ihema, which will be followed by the other affected lakes in the park. ORTPN is partnering with the Rwanda Green Foundation, a local conservation organization which is funded by the UNDP.

Ruzigandekwe explains that Rwanda Green foundation hires local labor around the park that uses boats to pull out the water hyacinth. He says this mechanical method of removing the water hyacinth is more effective compared to the hyacinth eating insects (the biological method) that they tried before.

Antoine Kapiteni, the coordinator of the project Integrated Management of Critical Ecosystems (IMCE) that works under the Lands and Environment Ministry has another view. According to him, the mechanical method of hand pulling at the water hyacinth is not that effective. He cites the example of women associations in Bugesera who have been manually removing the water weed and using it to make handcrafts. In his words, "they keep removing it, and it keeps on coming back. We have realized that that method does not work."

"So we have decided that it is necessary that a study be carried out to determine what really causes it and how best it can be controlled", he adds. Asked whether his project and its supervising ministry are not moving too slowly on an issue that could have devastating consequences, he replies this is not the case. "We are trying to find a comprehensive solution, that's why we want a study first, and we shall finish it before the end of this year", he says.

In some other countries, the abundant plants are being used for cattle food and in biogas production. Recently, the water hyacinth has also begun to be used in wastewater treatment due to their fast growth and ability to tolerate high levels of pollution.

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